The central goal of this research project is to characterize and optimize an original anticancer strategy for the treatment of Non-Hodgkin Lymphoma (NHL). NHL is predominantly a B-cell lymphoma for which nearly 67,000 new cases are expected in 2011 alone. Recently, preliminary in vitro and in vivo data demonstrated a new concept for treating this disease, which is based on the assembly of coiled-coil forming peptide motifs. Here, the assembly of coiled- coils was applied to crosslink CD20 receptors on B-cell surfaces, leading to specific induction of apoptosis in these cells. The utilization of structure-specific, coiled-coil motifs as tools to control cellular phenomena is a conceptually new approach that serves as a model for future designs. In this proposal, coiled-coils-defined as specific assemblies of alpha-helix peptides-are developed as molecular apoptosis inducing agents. A heterodimeric, antiparallel coiled-coil composed of CCE and CCK peptides was previously designed and showed high structural complementarity. For application in the apoptosis induction system, the CCE peptide was covalently attached to an anti-CD20 Fab', while multiple CCK peptides were conjugated as multiple grafts to a water-soluble polymer: N-(2- hydroxypropyl) methacrylamide. Interaction of Fab'-CCE with CD20 receptors on B-cell surfaces, followed by application of Polymer-CCKn, resulted in specific coiled-coil formation (CCE+CCK) at the B- cell surfaces, leading to CD20 crosslinking and subsequent apoptosis. Proof-of-concept was demonstrated in vitro and initial in vivo studies in mice. This proposal builds on the primary data by optimization of the coiled-coil design-both its physical stability an biocompatibility. First, a series of structurally unique coiled-coils will be carefully prepared an physically characterized. Second, in vitro and in vivo evaluation of the B-cell apoptosis induction (using the new designs) will be performed, followed by evaluation of the sample immunogenicity. We hypothesize that this optimization can lead to a significant enhancement in CD20 crosslinking and B-cell apoptosis. This proposal directly targets NHL, while also providing further design and functional information for the development of future anticancer approaches.